Mr Jones, who was forced to take the bus from Euston after Tube services were suspended, said: "He was standing next to me with a bag at his feet and he kept dipping into this bag and fiddling about with something.

"I was getting quite annoyed with this because it was a crowded bus.

"Everybody is standing face-to-face and this guy kept dipping into this bag."

Mr Jones, who said he got off the bus because it was in heavy traffic, has given a statement to police.

Police have yet been unable to establish whether a suicide bomber was responsible for the attack on the bus.

So far police have only confirmed that two people were killed on the bus.